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I have a project that I am in the midst of and need a #36 drill bit that can bore through some VERY hard steel. I've never seen steel this hard. Nothing that I have will even leave a mark on it. I will also need a 6-32 tap because I'm sure the ones that I have wont leave a mark on this stuff either.

Any ideas??? Suggestions???
 

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Take it to a machine shop that has a sinker EDM and they can burn the hole and thread it also. Bird Grinder is right if its that hard no tap will work but you can get a carbide drill and do the hole then take it to some one with a sinker EDM to burn the threads in it. Good luck and let us know how it turns out.
 

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Tron,carbide may be the answer.Don't know what your drill speed RPM is.
Try slowing the RPM down.Needless to ask you don't know what the grade of steel is.Could it be stainless?

Bocephas
 

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you could always get the piece annealed, and re hardened, a carbide drill might work, but I would stay away from the carbide taps..$$$, and they chip out by just looking at them too hard.

OSG, makes some good taps with coatings to get through hard stuff, just depends how hard it is.

an industrial tool supplier will have them in stock, or can get you one in a day. expect to pay $10 to $18 for a good tap.



tony
 

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Carbide HI-rock drill is the way to go. you can get them through Travers Tool or MSC. They look kind of like a gun drill two straight flutes. You'll need all the luck in the world to tap it and then some more luck,if it's hardened.your weclomce Lou
 

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Tron, if its stainless you might have a very hard alloy like valve or tool type stainless. Is it magnetic? If it is, its probably a 300 series type stainless and machinable. If its non-mag it has nickel in it, and probably a 400 series, and most are machinable. However some 400 series like 440 (razor steel) are very, very hard. Good luck, Wayne
 

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EDM would be the best way.

Tron You do not know the kind of alloy you are dealing with. Some will work harden on your butt while you try to cut it. Inconel will get very hard quick if it gets hot while drilling or turning.

There are so many exotic alloys out there and hardly any information on how to work them. And a hole that small in very hard metal is about impossible to drill
by hand. Maybe in a vise on a mill but even that is a bit#h.

And then you have to put the wrinkles in it.

Rock

Jim
 

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What is the piece used for, does it have to be hardend when done? If not you can anneal it. Heat it to a orangish color and slowly let it cool
 

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Tron it could be a number of different tool steels there are tons out there some are A2,D2,H21,M4 and P20 they are all very tuff when hardened when I have to machine D2 or P20 I know I am in for a long night. Trying to drill a hole that small in something that hard is like pissing in the wind. The sinker EDM is the only way to go if you can find one.
 

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Do a simple test -- can you file it? If not, forget about drilling and tapping. 400 series stainless are magnetic and most can be heat treated. You will just break drills and taps. EDM is the answer, but you will find out that it will be an expensive hole.

JEB
 

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Joe, are you drilling thru a diameter, or on a flat?
Sounds like steel that's been heat treated. You'd have to have it annealed back before anything short of carbide or diamond will cut it. Tapping it in that condition is probably not feasable.

show us a picture!!....
 

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Sounds like stellite. Depending on what and where it goes.. I'd use a diamond drill that oversized. the make a round insert and locktite it in place.. If all you need is a 6X32 thread.. you'll break the screw before you pull a 5/16 locktited sleeve out..
 

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Tron, If you EDM the hole you still will not get a tap to cut the threads. If you drill with carbide you still won't be able to tap.
A trick I use on hardened receivers or allready hardened steel is, Get a 12 volt battery and a air-arc rod. You can use heavy jumper cables. Sharpen the end of the air-arc rod like a pencil, hook up the cables to the work and the rod. Put the point of the rod on the exact spot you are going to drill. It will get red hot in a hurry. wear good gloves. Once red, remove the rod and let cool. You will be able to drill,tap the hole. No need to re heattreat because you just annealed a spot.
A old Indian tought me that trick.
Stu
 

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Dednlost, that was not Tron's question.......

PBB, stellite, or any form of cobalt, would be a bugger for sure....
 
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